Well, an actual para, known as a m249 SAW(Squad Automatic Weapon) does not have the caliber to go through a car and such. It is actually the same caliber as the m16a2 service rifle, which is a 5.52 Nato round. So unless in-game it's equipped with sabot AP(Armor Piercing) rounds, it won't go through a vehicle. Same caliber round as the m4a1 colt carbine as well. But an AK might go through a vehicle, as long as it doesn't have to penetrate the engine block itself. The AK usually is a 7.62 round, the same as my 240G crew-served machine gun that I carry. But the m2HB .50cal machine gun will go through just about anything. To hell with going through a wall, that bad boy will go through a building. It can demolish an engine block and such. The deagle is the same caliber as the m2HB, but does not deliver a round with the same energy per square foot. The deagle will kick like a mofo, but the m2HB will make the jeep it's mounted on recoil.
Just a quick weapons lesson from a future Marine Corps Gunner